Compressed air intensifier



Feb. s, 1944.,

G. N. CADBURY 2,340,929

COMPRESSED AIR INTENS IFIER 'Filed June' 23, 1941 A Patentecl Feb. 8, 1944 '2,340,929' COMPRESSED AIR. INTENSIFIER George Norman Cadbury, West Bromwich, England, assignor to E. M. B. Company Limited, West Bromwich, England Application June 23, 1941, Serial No. 399,375

In Great Britain August 21, 1940 1 Claim.

In the specicaticn of my patent application No. 347,323 I have described an invention relating to compressed air intensiers for use more particularly with die casting machines. The present specification is concerned with a modi- Iication of the said invention whereby the apparatus supplied by the intensier can readily be enabled to meet a wide range of different working conditions.

The present invention comprises in combinachine 1J or other apparatus to be supplied with tion an intensifier as claimed in my earlier specicompressed air, whilst the valve q controls comcation above mentioned, operating valves assomunication between the latter pipe and an outciated with the low pressure part of the intensilet u to atmosphere in the-chest 1'. Movement fier, other operating valves associated with the of the lever s in one direction opens the valvep high pressure part of the intensier and interand allows the valve q to close, and opposite connected with the first mentioned valves, a bymovement of the lever has the reverse effect. pass situated between the rst mentioned valves The two valve-operating levers h, s are interand the delivery side of the second mentioned connected by, for example, a link w, so thatthe valves, a non-return valve in the by-pass, and valve e for admitting compressed air to the also a regulating valve or valves in the by-pass. low-pressure part c of the cylinder is opened and The accompanying drawing is a diagrammatic closed concurrently with the valve p for admitsectional elevation of apparatus constructed in ting compressed air from the high-pressure pant accordance with the invention for supplying d of the cylinder to the casting machine 'v or compressed air to a die casting machine or other other apparatus, and so that the valve f for exapparatus. hausting` air from the low-pressure cylinder part In carrying the invention into eiect as shown, is opened and closed concurrently with the valve I employ an intensier comprising a slidable ram q for releasing air from the casting machine or having a pair of coaxial parts a, b of different other apparatus. By interconnecting the operdiameters and mounted in a cylinder having ating levers of the two pairs of valves I obviate parts c, d of corresponding different diameters any risk of accidental escape from the intensias described in my specification above mentioned. er, while the latter is not in action, of air ad- Movement ci the ram a, b in one direction is mitted to the high-pressure part of the cylinelected by compressed air acting on the outer der. end of the larger part a of the ram, and the re- For some purposes it is desirable to set a lower turn is eiected by gravity, compressed air or a limit to the pressure at which air is discharged spring. Air is admitted to and exhausted from from the high-pressure part d of the cylinder. the larger or low-pressure part c of the cylin- In other words, it is desirable to ensure that the der under the control of a pair of spring-loaded pressure shall reach a predetermined value before poppet type valves e, .f arranged in a chest g, discharge commences after the intensier has these valves being operable by a common lever h. been set in motion. To meet this requirement, The valve e controls communication between a I secure or form on the Outer end 0f the highcompressed air supply pipe i and another pipe :i pressure cylinder part d a hollow cylindrical exleading to the low-pressure part c of the cylinder, 1161151011 il in Which S Sldably mounted an adwhilst the valve .f controls communication be- .instable valve of hollow cylindrical form for tween the pipe leading to the low-pressure part Controlling communication between the highof the cylinder and an outlet pipe lc leading to pressure cylinder part and its delivery pipe 0. the atmosphere through a hollow extension c1 of inner end 0f the Valve being 0f C10Sed 00111081 the cylinder. Movement of the lever h in one fOrm and adapted to cro-operate with a compledirection opens the valve e and allows the valve mentaly Seating Z/ in the eXteIlSOH, and the def to close, and opposite movement of the lever livery pipe being COIlIleCted '60 the eXeIlSiOn at is accompanied by the reverse eeet, the side of the valve seat'ng remote from the The Smeuer or highpressure part d of the cylinder. The valve a: is held on its seating by Cylinder is .provided with e, non retum veuve m a spring z situated in the interior of the cylinder past which compressed air from a branch pipe n eXtenSOIl d1, and the pressure eXerted by the communicating with the supply pipe z' can ow 55 Spring can be adjusted by a Screw 2 passing into that part of the cylinder. AlsoI the highpressure part d is provided at its outer end with a delivery pipe o having associated with it a pair of spring-loaded poppet valves p, Q similar'to those above described. The valves p, q are arranged in a chest r and are operable by a common lever s. The valve p controls communication between the delivery pipe o and another pipe t leading to the die casting mapipe I0, the pressure of this air :choke valve l2, and

"other apparatus from the high 2 through a cover 3 on the outer open end of the extension. The screw 2 is adapted to act on the spring z through a thrust piece 4, in the cylinder extension d1, and is provided at its outer end with a hand operable hollow actuating head 5 suitably graduated to indicate the pressures required. Before the valve :r can be lifted off its seating a predetermined pressure vmust be attained in the high-pressure part d of the cylinder. When this pressure is reached the valve a: opens and establishes communication between the high-pressure part d of the cylinder and the delivery pipe o, the valve being thereafter held off its seating by the air pressure acting on the closed end of the valve.

is released the valve :E is returned by its spring a'. In the cylinder extension cover 3 is provided an adjustable vent 6. To prevent air' from leaking past the valve :c to the vent B When this valve is open, the cover 3 is provided with a seating 1 against which the outer open end of the vvalve 'can'abut when the latter is infits open position.

For regulating the pressure at which `compressed air is-admitted to the low-pressure 'cylinder parte, an adjustable reducing valve' and an adjustable choke valve 9 may be provided inthe supply pipe i.

To the pipe j interconnecting the valve chest g and the low pressure part c of the cylinder I connect one end of a by-pass pipe I0, and I connect theother end of the latter pipe to the pipe t interconnecting the other valve chest r and the die casting machine v or Vother apparatus to be supplied-with compressed air from the intensifier. In the by-pass pipe l0 is arranged a non-return valve ll, an adjustable choke valve l2, and (if desired) lan adjustable reducing valve I3.

The apparatus above described is `such that `on' admitting relatively low pressure air to the low pressure part c of the intensier, air is at 'the same time supplied to the die casting ma- `'chine 1J or other apparatus through the-by-pass being variable to yrequirements by adjustment of the also of the regulating valve Subsequently air at high ypresthe die casting machine'u or pressure-part dof ksuit different I3 (when used). sure is supplied to y A full area of the When the air pressure the intensifier when the pressure in the latter becomes sufficient to open a loaded valve :r situated in the extension d1 of that part.

By the use of a by-pass in combination with the intensifier and operating valves as above described I am able to effect the operation of a die casting machine and to adjust the working conditions to suitdifferent alloys in a very satisfactory and convenient manner.

The invention is not limited to the example 'above described as subordinate constructional details may be varied. Moreover whilst the invention is especially intended for use with die casting machines it may be applied to other analogous ruses Where 'it can be advantageously employed.

`Having thus described my invention what I Vclaimas new and desire to secure by Letters Paten't fis: v

Means for supplying compressed air to a die casting machine or other apparatus, comprising in combination a ram having va lpairof parts of different diameters,v a cylinder in which the ram -isfarranged and which is provided with high and :low pressure parts of Aappropriately differentdiameters for accommodating the ram parts, the ram and cylinder being capable of relative slid- -ing movement under theaction of lcompressed -air in the direction for compressing air in the high pressure cylinder part, a non-return valve -past which air can flow .to'thehigh pressure ypart of the cylinder, inlet and exhaust valves f associated with the low pressure partof the cylinder, a. delivery valve associated with the high pressure part of the cylinder, a passage through which compressed air from the high pressure part of the cylinder can flow under the control of the delivery valve, an air-release valve associated with the said passage, means whereby the inlet and exhaust valves are operatively interconnected with the delivery and air-release valves, a by-pass situated between the inlet valve and a part oi the said passage at the side of the delivery and air-release valves remote from the ram,

` a non-return valve arranged in the by-'pass so that air from the inlet valve can flow through the by-pass to the said passage, and at least one 4regulating valve in the by-pass.

GEORGE NORMAN CADBURY. 

